exclude_by_velocity: Remove trajectories entirely, based on velocity thresholds

In pathviewr: Wrangle, Analyze, and Visualize Animal Movement Data

Remove trajectories entirely, based on velocity thresholds

Description

Remove trajectories from a viewr object that contain instances of velocity known to be spurious.

Usage

exclude_by_velocity(obj_name, vel_min = NULL, vel_max = NULL)

Arguments

obj_name	The input viewr object; a tibble or data.frame with attribute pathviewr_steps that includes "viewr"
vel_min	Default NULL. If a numeric is entered, trajectories that have at least one observation with velocity less than vel_min are removed.
vel_max	Default NULL. If a numeric is entered, trajectories that have at least one observation with velocity greater than vel_max are removed.

Value

A new viewr object that is identical to the input object but now excludes any trajectories that contain observations with velocity less than vel_min (if specified) and/or velocity greater than vel_max (if specified)

Author(s)

Vikram B. Baliga

Examples

## Import and clean the example Motive data
motive_import_and_clean <-
  import_and_clean_viewr(
    file_name = system.file("extdata", "pathviewr_motive_example_data.csv",
                            package = 'pathviewr'),
    desired_percent = 50,
    max_frame_gap = "autodetect",
    span = 0.95
  )

## See the distribution of velocities
hist(motive_import_and_clean$velocity)

## Let's remove any trajectories that contain
## velocity < 2
motive_vel_filtered <-
  motive_import_and_clean %>%
  exclude_by_velocity(vel_min = 2)

## See how the distribution of velocities has changed
hist(motive_vel_filtered$velocity)

pathviewr documentation built on March 31, 2023, 5:47 p.m.